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What is a lava tube?

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Hello and welcome to CoreFacts, where we're always short on time and big on science. I'm Dane Klima.

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Now back to CoreFacts. Today's question is about Lava Tube.

What is a lava tube?

During long-lived eruptions, lava flows tend to become "channeled" into a few main streams. Overflows of lava from these streams solidify quickly and plaster on to the channel walls, building natural levees that allow the level of the lava to be raised. Lava streams that flow steadily in a confined channel for many hours to days may develop a solid crust or roof and thus change gradually into streams within lava tubes. Because the walls and roofs of such tubes are good thermal insulators, lava flowing through them can remain hot and fluid much longer than surface flows.

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